In article <832.29883ef2 at nphi.fi>, tronni at nphi.fi writes...
(edited for brevity)
>Sometimes a yellow strip appears in the blue front
>when a minigel is run (30 mA per gel). The samples
>in lanes affected by the yellow strip stop migrating
>immediately. We have not found out any clear reason
>for this phenomenon. Buffers are new, as are the
>other reagents we use. As a sample buffer I use 2 x Laemmli
>sample buffer including 10 % beta-mercaptoethanol.
>>Does anybody have any troubleshooting suggestions or similar
>experiences?
>I've had the same thing happened to me when my samples were acidic (as
after TCA precipitation, for example). When I took some of the sample
buffer and added some acid to it I found that it turned yellow. I
thought then that probably the color of the coomassie
brilliant blue is yellow at low pH. However, I found that my samples
still migrated OK. (But it probably was because I was running regular
size gels and there was enough buffering capacity to allow my samples
to run fine).
beatriz at ufpinebeatriz at pine.circa.ufl.edu
Cuando suena el reloj despertador por la man~ana, recuerdo que "al que
madruga Dios lo ayuda", pero como "nunca es tarde si la dicha es buena"
y "no por mucho madrugar amanece mas temprano", sigo durmiendo.